With the continued improvements in roller cutter drill bits each portions of the structure which may possibly fail has come under intense scrutiny. With improvements in bearings, seals and lubrication systems the life of drill bits has been increased dramatically. One weakness of drill bits using ball bearings is that the ball bearings require the use of a passageway through the bit body for the loading of the balls after the roller cutter has been positioned on its journal and thereafter the ball loading hole has been closed by welding a plug in its outer end. It is believed that the welding of such plug has created problems which have limited the useful life of the drill bit. It is believed that the ball loading plug welds have been the source of fatigue failures due to heat affected zones, sharp corners formed at the edge of the hole and the weld metal and residual stresses. Further in an effort to avoid excessive temperatures to which the lubricant seal is exposed such welding has been done under water. In such cases the entry of water into the lubrication system would substantially limit the life of the drill bit.